(1) Field of the Invention
This invention relates to a machine suitable for use in spreading and laying a seed nursery strip, especially, a lawn nursery strip, and more specifically to a machine for automatically spreading and laying a seed or lawn nursery strip at a high speed over a bare ground and at the same time, sprinkling a predetermined amount of top dressing soil automatically and evenly over the thus-spread and laid lawn nursery strip.
(2) Description of the Prior Art
Seed nursery strips have each been produced by distributing seeds, fertilizers and the like between two layers of paper sheets, non-woven rayon fabrics or the like and then bonding them at suitable locations. In order to dry the thus-applied binder or glue, this conventional production process requires a drying step. Accordingly, such conventional seed nursery strips were accompanied by a drawback that due to the heat applied during the heating step, the germination percentages of their seeds were lowered.
Upon rooting, germination and subsequent growth of lawn grass seeds, their roots have high elongation pressures while their sprouts are prevented from growing even by slightest contact to obstacles. It is therefore indispensable to avoid such obstacles.
The above drawbacks have been solved by seed nursery strips proposed by one of the present inventors (see, U.S. Pat. No. 4,066,490 issued Jan. 3, 1978 to Mitsuru Yoshimi and entitled "METHOD FOR PRODUCING A LAWN NURSERY STRIP", which is incorporated herein by reference.). However, the above-proposed seed nursery strips have a tensile strength as low as 5 kg/cm. When they are laid manually, they tend to develop crumples if they are pulled by somewhat large forces in their longitudinal directions, thereby lifting them up from the ground. Even if the seeds in the thus-lifted seed nursery strips are allowed to germinate owing to water sprinkled after their spreading and laying, they cannot propagate their roots into the ground and thus result in death. When spreading and laying such seed nursery strips manually, it requires considerable skill in sprinkling top dressing soil evenly to a thickness of 3-5 mm over the thus-laid seed nursery strips. If workers step on the thus-laid seed nursery strips, they may undesirably be cut off or crumpled. Furthermore, their spreading and laying work requires lots of manpower and tremendous labor.